Obstetrics and Gynecology

Pelvic Inflammatory Disease (PID)

Pelvic Inflammatory Disease

1. What every clinician should know

Pelvic inflammatory disease (PID) is characterized as an upper genital tract infection in women that is associated with serious sequelae. PID results from the spread of microbes from the vagina through the cervix into the uterus, fallopian tubes, and peritoneal cavity. It represents a spectrum of infections which may include endometritis, salpingitis, oophoritis, pelvic peritonitis, tubo-ovarian abscess, and perihepatitis. Although PID is most often polymicrobial, specific organisms commonly associated with cervicitis and upper genital tract infection includes: Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, and Mycoplasma genitalium.

PID can present in an acute or subclinical state. Acute PID is most often associated with severe abdominal or pelvic pain. Other symptoms include vaginal discharge, dyspareunia, dysmenorrhea, dysfunctional uterine bleeding, postcoital bleeding, dysuria, low back pain, nausea and vomiting, and fever. Patients with ruptured tubo-ovarian abscesses may appear septic and require immediate medical attention. Patients with subclinical PID are more well-appearing and may have vague symptoms.

Risk factors associated with PID include:

1. sexual activity, especially with multiple partners

2. a history of sexually transmitted infections (STIs)

3. lack of barrier contraceptive use

4. concurrent vaginitis, such as BV

5. intercourse during menstruation

6. tobacco use

7. gynecologic procedures involving cervical dilation

8. douching

2. Diagnosis and differential diagnosis

Diagnosis

PID is a clinical diagnosis and other morbid conditions (i.e. appendicitis) must be excluded when evaluating the patient. PID is diagnosed based on history and clinical exam. According to CDC recommendations, patients presenting with symptoms suggestive of PID, risk factors for STIs, and pelvic organ tenderness on exam should be treated empirically due to the sequelae of untreated infection. The diagnosis of PID according to clinical criteria is confirmed with diagnostic laparoscopy in approximately 65% of patients, so the sensitivity of these criteria is low. However, in order to capture more mild-moderate (subclinical) cases, it is prudent to treat empirically.

There are major and minor criteria to aid the clinician in making the diagnosis. Any one of the three major criteria along with clinical suspicion (abdominal or pelvic pain with risk of STIs) should be considered for empiric therapy.

Minor criteria may increase the clinician’s suspicion and improve the specificity of exam findings for the diagnosis of PID. These include: fever >101°F, leukocytosis, leukorrhea on microscopy of vaginal fluid, and elevated erythorcyte sedimentation rate (ESR) or elevated C-reactive protein.

A pelvic exam should be performed to determine if pelvic organ tenderness is present. The clinician should inspect the cervix for mucopus or friability. A nucleic acid amplification test (NAAT) for gonorrhea and Chlamydia should be collected. Vaginal fluid should be collected for microscopy (wet mount) and inspected for leukorrhea, bacterial vaginosis, and Trichomonas. All patients diagnosed with acute PID should be screened for HIV infection.

If a pelvic mass is detected on pelvic exam, it is advisable to order a transvaginal pelvic ultrasound to rule out tubo-ovarian abscess, which is present in approximately 30% of patients admitted for PID. The gold standard for diagnosis remains diagnostic laparoscopy, but this is not feasible or necessary in many settings. In patients in whom appendicitis is suspected, computed tomography (CT) of the abdomen-pelvis should be ordered.

Endometritis can be confirmed by obtaining an endometrial biopsy for histology and culture. This diagnostic tool has been used in reach but is not necessary for the clinical diagnosis and management of PID.

Differential Diagnosis

Appendicitis: In order to exclude appendicitis, a CT scan of the abdomen and pelvis can be ordered.

Ovarian Torsion: Ovarian torision is also a diagnosis of exclusion and based on history and physical exam. If the patient’s history is suggestive of ovarian torsion and this cannot be excluded, it is best to proceed with a diagnostic laparoscopy in order to avoid loss of the affected adnexa.

Ruptured Ovarian Cyst or Hemorrhagic Corpus Luteum: A pelvic ultrasound may help to differentiate PID from a ruptured ovarian cyst, but these may be difficult to differentiate and a diagnostic laparoscopy may be required.

Ectopic Pregnancy: PID during pregnancy is very rare. In the case of a patient presenting with symptoms of an ectopic pregnancy (abdominal pain, spotting, and positive pregnancy test), this patient should be evaluated for ectopic pregnancy before the diagnosis of PID is considered.

Cystitis/Pyelonephritis: Patients with significant cystitis may have abdominal and pelvic pain. They may have pain when palpating the bladder during bimanual exam or low back and costovertebral angle (CVA) pain with pyelonephritis. A urinalysis may be collected to determine if the etiology of infection is more likely a urinary pathogen rather than PID. These patients are also less likely to have cervical mucopus, leukorrhea, or cervical motion tenderness.

Diverticulitis: patients with suspected diverticulitis or rupture diverticulum should be evaluated with a CT scan of the abdomen and pelvis.

3. Management

The goal of PID treatment is to provide broad spectrum antimicrobial therapy that will cover any of the likely pathogens. Most PID infections are polymicrobial and involve a mix of aerobic and anaerobic microorganisms. All therapeutic regimens used to treat PID should adequately treat gonorrhea, Chlamydia, gram-negative enteric bacilli, streptococci, and anaerobes. Patients with concurrent bacterial vaginosis should receive additional therapy to treat vaginitis.

Patients with mild-moderate PID may be treated as outpatients, whereas women with more severe acute PID may require hospitalization and parenteral therapy. Outpatients should follow up within 48-72 hours to determine if they are symptomatically improving and if not admission should be considered. Criteria for admission include:

nausea and vomitting with inability to tolerate oral therapy

high fever or severe clinical illness

tubo-ovarian abscess

inability to comply with therapy and follow up

cannot exclude surgical condition, i.e. appendicitis

pregnancy

Various emperic antimicrobial regimens have been studied. Due to rising gonococcal fluoroquinolone resistance, this drug class is no longer considered adequate as a component of therapy. Physicians must consider drug availability, cost, and patient tolerance when determining which regimen is best for the individual patient.

A high clinical suspicion and readiness to provide emperic treatment in women at risk are the best strategies for lowering a woman’s risk for long-term sequelae. Early recognition and treatment of PID are key in decreasing a woman’s risk of long-term sequelae.

Consequences of Treatment

Consequences of therapy are rare. Patients may have an adverse reaction to the antimicrobial therapy provided. Patients with large tubo-ovarian abscesses may not respond to parenteral antibiotics and may require surgical drainage of the abscess. Hysterectomy is rarely needed to treat PID.

5. Prognosis and outcome

Prognosis and Outcome

Approximately 25% of patients diagnosed with acute PID develop long-term sequelae. The risk for sequelae is increased if the patient has recurrent episodes of PID.

Tubal factor infertility (TFI) – TFI occurs in approximately 8-19% of women after one episode of PID. This is more likely in women with severe acute PID and delayed therapy.

Ectopic pregnancy – this is a potential life-threatening complication of upper genital tract infection. Approximately 2-6% of women with a history PID experience an ectopic pregnancy.

Chronic pelvic pain (CPP) – CPP affects approx 12-24% of women with a history of PID. CPP as a consequence of PID has been studied less extensively than TFI and ectopic pregnancy.

Long-term Impact

Patients with a history of PID are at risk for recurrent upper genital tract infections. These women should be educated about risks associated with PID, such as lack of barrier contraception use and douching, in order to decrease their risk of recurrence. They should also be made aware of the symptoms associated with PID and advised to seek medical attention if they develop such symptoms. Despite treatment, patients may develop long-term sequelae such as chronic pelvic pain, infertility, and ectopic pregnancy.

6. What is the evidence for specific management and treatment recommendations

Workowski, KA, Berman, S. “Sexually transmitted diseases treatment guidelines, 2010”. MMWR Recomm Rep. vol. 59. Dec17. pp. 1-110. (The CDC STD Guidelines are an excellent resource for clinicians in regards to the treatment of pelvic inflammatory disease. These guidelines are composed by a panel of experts. The recommendations made are based on the existing evidence and the publications perceived to be most influential in PID research and management.)

Soper, DE. “Pelvic inflammatory disease”. Obstet Gynecol. vol. 116. 2010. pp. 419-28. (Dr. Soper is one of the contributing authors to the PEACH trial. This review paper in Obstetrics and Gynecology is an excellent up to date source for PID pathophysiology, diagnosis, treatment, and long-term outcomes.)